A round pipe of varying diameter carries petroleum from a wellhead to a refinery. At the wellhead the pipe\'s diameter is 58.7 cm (0.587 m) and the flow speed of the petroleum is 12.7 m/s. At the refinery the petroleum flows at 6.27 m/s. What is the volume flow rate of the petroleum along the pipe and what is the pipe\'s diameter at the refinery?